GMV GSharp® Going to Orbit: GSharp Evolution for On-Board Real-Time POD in LEO Satellites

J.C. López, L. Bravo, A. Chamorro, S. Camargo, J. González, A. González, J.D. Calle

Abstract:	GMV GSharp®—a safety-driven, embedded-ready PPP/PPP-RTK positioning engine—has been enhanced with a reduced-dynamics architecture and an orbit propagation module tailored to LEO. The engine processes uncombined multi-constellation measurements and supports Galileo HAS corrections for real-time operation. The dynamic model includes high-order gravity, third-body effects, SRP with shadowing, atmospheric drag (NRLMSISE-00), and relativistic accelerations, integrated at 1 Hz via RK4 within a sequential EKF. Validation with real data from SENTINEL-6A and SWARM-B shows on-orbit 3D RMS orbit errors around 10–15 cm using HAS, and clock errors around 0.6–0.7 ns (P68). We further quantify short-horizon prediction performance to support autonomous functions. These results confirm flight-readiness of GSharp® for on-board, real-time LEO POD. This paper is organized as follows: Sec. 2 overviews the engine, Secs. 3–4 detail the propagation and estimation, Sec. 5 presents the test campaign and datasets, Sec. 6 discusses results, and Secs. 7–8 summarize conclusions and future work.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	1327 - 1337
Cite this article:	López, J.C., Bravo, L., Chamorro, A., Camargo, S., González, J., González, A., Calle, J.D., "GMV GSharp® Going to Orbit: GSharp Evolution for On-Board Real-Time POD in LEO Satellites," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 1327-1337. https://doi.org/10.33012/2025.20413
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